On Mon, Sep 02, 2019 at 08:47:02PM +0200, Jacek Anaszewski wrote: > On 9/2/19 8:12 PM, Greg KH wrote: > > On Sun, Sep 01, 2019 at 06:53:34PM +0200, Jacek Anaszewski wrote: > >> Hi Akinobu, > >> > >> Thank you for the patch. > >> > >> I have one nit below but in general it looks good to me. > >> I've tested it with 2000 mtd triggers (~14kB file size) > >> and it worked flawlessly. > >> > >> Still, I would like to have ack from Greg for it. > >> > >> Adding Greg on Cc. > >> > >> On 8/29/19 4:49 PM, Akinobu Mita wrote: > >>> Reading /sys/class/leds/<led>/trigger returns all available LED triggers. > >>> However, the size of this file is limited to PAGE_SIZE because of the > >>> limitation for sysfs attribute. > >>> > >>> Enabling LED CPU trigger on systems with thousands of CPUs easily hits > >>> PAGE_SIZE limit, and makes it impossible to see all available LED triggers > >>> and which trigger is currently activated. > >>> > >>> This converts /sys/class/leds/<led>/trigger to bin attribute and removes > >>> the PAGE_SIZE limitation. > > > > But this is NOT a binary file. A sysfs binary file is used for when the > > kernel passes data to or from hardware without any parsing of the data > > by the kernel. > > > > You are not doing that here, you are abusing the "one value per file" > > rule of sysfs so much that you are forced to work around the limitation > > it put in place on purpose to keep you from doing stuff like this. > > > > Please fix this "correctly" by creating a new api that works properly > > and just live with the fact that this file will never work correctly and > > move everyone to use the new api instead. > > > > Don't keep on abusing the interface by workarounds like this, it is not > > ok. > > In the message [0] you pledged to give us exception for that, provided > it will be properly documented in the code. I suppose you now object > because the patch does not meet that condition. Well, I honestly don't remember writing that email, but it was 5 months and many thousands of emails ago :) Also, you all didn't document the heck out of this. So no, I really do not want to see this patch accepted as-is. > Provided that will be fixed, can we count on your ack for the > implementation of the solution you proposed? :-) Let's see the patch that actually implements what I suggested first :) thanks, greg k-h
